This in vitro study attempts to delineate the role of extracellular matrix (ECM) constituents at the epithelial tissue-implant interface. To know which ECM constituents have a beneficial influence on the behavior of epithelial cells, the attachment, proliferation, morphologic pattern, and differentiation or cytoskeletal organization of human oral epithelial cells on ECM-coated (type IV collagen, fibronectin, type I collagen, laminin, and vitronectin) and noncoated titanium surface have been evaluated and compared. In each experiment comparing commercially pure titanium and oxygen plasma-cleaned titanium, the same ECM constituents were used. In this study, type IV collagen could provide an excellent substratum for epithelial cell attachment on titanium surface, but vitronectin-coated titanium revealed lower effectiveness for attachment of epithelial cells than noncoated titanium. These results suggested that type IV collagen could be used as a means for obtaining good epithelial seal, whereas vitronectin could be used to restrain the attachment of epithelium to dental implants. Keywords: cell attachment, cell proliferation, extracellular matrix protein, implant, oral epithelium, titanium